add include files from llvm used by subzero into doxygen

Doxyfile

Index: Doxyfile
diff --git a/Doxyfile b/Doxyfile
index c9da93981b8309750792b93022821f1ada3f713c..077b4cba858831cb0e7fc902a70d62b6bb9bbdbd 100644
--- a/Doxyfile
+++ b/Doxyfile
@@ -298,7 +298,7 @@ AUTOLINK_SUPPORT       = YES
 # diagrams that involve STL classes more complete and accurate.
 # The default value is: NO.
 
-BUILTIN_STL_SUPPORT    = NO
+BUILTIN_STL_SUPPORT    = YES
 
 # If you use Microsoft's C++/CLI language, you should set this option to YES to
 # enable parsing support.
@@ -743,7 +743,13 @@ WARN_LOGFILE           =
 # spaces.
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = "src"
+INPUT                  = "src" \
+                         "../llvm/include/llvm/ADT" \
+                         "../llvm/include/llvm/Bitcode" \
+                         "../llvm/include/llvm/Config" \
+                         "../llvm/include/llvm/IR" \
+                         "../llvm/include/llvm/IRReader" \
+                         "../llvm/include/llvm/Support"
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -769,7 +775,7 @@ FILE_PATTERNS          =
 # be searched for input files as well.
 # The default value is: NO.
 
-RECURSIVE              = NO
+RECURSIVE              = YES
 
 # The EXCLUDE tag can be used to specify files and/or directories that should be
 # excluded from the INPUT source files. This way you can easily exclude a
@@ -1927,7 +1933,7 @@ SEARCH_INCLUDES        = YES
 # preprocessor.
 # This tag requires that the tag SEARCH_INCLUDES is set to YES.
 
-INCLUDE_PATH           =
+INCLUDE_PATH           = ../llvm/include
 
 # You can use the INCLUDE_FILE_PATTERNS tag to specify one or more wildcard
 # patterns (like *.h and *.hpp) to filter out the header-files in the